For an everyday driver the tranny is fine w/ no mods, if you want to get some fuel/air and make some power you would want to get one w/ a NV5600
(00-04) rather than a G56 (04.5-current). now you can do a nv5600, G56 swap takes a little bit but can be done.

i would go 06+ on a 2500 hemi. 03-05 have tow haul mode but no way to keep it from shifting into overdrive. 06+ you hit the button once to put it into tow haul mode where it locks out your 5th gear overdrive but still uses 4th gear overdrive. hit the button again to put it in third (direct drive) and lock out both overdrive ratios (4th and 5th). lots of 03-05 drivers complained about the gear hunting between 3rd and 4th with a heavy load and it caused more wear on the trans. the ctd seem to be fine when left stock.